Confocal

The Nikon MicroscopyU Confocal Image Gallery features digital image sequences captured using a Nikon PCM-2000 confocal microscope scanning system coupled to an Eclipse E-600 upright microscope. Successive serial optical sections were recorded along the optical axis of the microscope over a range of specimen planes. These sequences are presented as interactive Java tutorials that allow the visitor to either "play" the series of sections automatically, or to utilize a slider to scroll back and forth through the images.

Abscission Layer

Each new leaf forms a specialized layer of cells called an abscission that is located between the leaf and the stem and is responsible for the changing colors of leaves in the fall season. The abscission layer is comprised of minute tubules designed to transport water to the leaf and carry carbohydrates back into the tree. In the autumn, the green color, which dominates trees throughout the spring and summer, fades to reveal the color of pigments that have been present in the leaf all along, such as orange and bright yellow.

Alfalfa Stem

Alfalfa, or Medicago sativa, is a deep-rooted perennial native to the Mediterranean region near Iran but which also grows well in North America and Western Asia. Also called Lucerne, or Purple Medic, it looks very much like clover with a smooth, erect stem growing 2-3 feet tall, grayish-green feathery trifoliate leaves, and egg-shaped leaflets.

Apple Cedar Rust

Cedar apple rust (CAR) is a disease affecting apple trees in North America east of the Rocky Mountains. It is caused by the fungus Gymnosporangium juniperi-virginianae and can defoliate trees and blemish fruit making them unmarketable.

Auerbach's Plexus

The Auerbach's plexus lies between the longitudinal (outer muscle layer) and circular muscular (inner) coats of the duodenum. Peristaltic movements of digesting material originate in the muscles (myogenic) and are initiated by local reflexes.

Basal Cell Carcinoma

A common form of skin cancer (90 percent of the cases), basal cell carcinoma may grow slowly at first, but like other malignant cancer cells, can spread to other parts of the body (metastasize). It is estimated that 500,000 new cases of this type of non-melanoma skin cancer occur in the United States each year with about 2,000 deaths annually.

Basswood (Tilia) Stem

The American Basswood, Tilia americana, is a treasured hardwood tree of the Eastern and Central United States. It has a tall, straight trunk and rounded crown that provides excellent shade during the hot summer months.

Basswood (Tilia) Root

The American Basswood is a stately and graceful hardwood tree that grows abundantly in rich moist soil found in the eastern half of North America. The heavily foliaged crown produces dark green heart-shaped leaves that reveal lighter colored glistening undersides when blown by a breeze.

Beach Grass (Marram)

Marram is the common name for a beach grass that grows on the sandy coasts of Europe, North America, and North Africa and is also known as psamma or sand reed. These course and hardy grasses grow in tufts producing tightly rolled spike-like leaves that are naturally resistant to wind and salt spray.

Bordered Pits

Bordered pits are structures found in the conductive tissues of many plants that allow fluids to pass from one cell to another. The tracheids, which transport liquids, are dead cells; their contents decomposed, they are essentially empty. Simple pits are areas of the tracheid cell wall so thin that nutrient rich solutions can pass through them, to be dispersed throughout the plant.

Cabbage Club Root

Wilted, yellowing leaves and stunted plants can often signal an infection of club root in cruciferous plants such as cabbage, cauliflower and broccoli, causing significant economic losses to farmers. The most distinctive symptom, however, is the abnormal enlargement, or clubbing, of roots where the disease process is taking place.

Cerebral Cortex

The cerebral cortex is the part of the brain that sets humans apart from and above all other animals. This sector is primarily responsible for interpreting information sent by the senses such as sight, sound, smell and touch as well as initiating voluntary directed action such as walking or talking.

Cherry Flower Bud

Cherry is the name given to several varieties of trees that produce small, almost heart-shaped globular edible fruits that vary in color from deep red to nearly black. The native habitat of the cherry is believed to be woodlands of Europe and Asia.

Chick Embryo (60 to 70 Hours)

The chicken is a common domesticated fowl and is commercially valued for meat, eggs, and feathers. Domestic chickens are descended from the wild red jungle fowl that is native to Southeast Asia, which is believed to have been domesticated as far back as 8,000 years ago.

Chlamydomonas

Chlamydomonas is a large genus of common green algae that are equipped with two relatively long whip-like appendages used for locomotion. Primarily aquatic, algae are found anywhere there is marine and freshwater, moist soil, and even snow.

Chinese Hamster Ovary Cells, Specimen 1

Chinese hamsters are Old World rodents characterized by soft thick fur, large expandable cheek pouches, and relatively long tails. Because this small breed of hamster has a slender body and a tail that is unusually long, it is thought to resemble a mouse and is often referred to as "mouster".

Chinese Hamster Ovary Cells, Specimen 2

Chinese hamsters are nocturnal creatures -- they are active at night and sleep during most of the day. Similar to other rodents, these animals rely heavily on the sense of smell and hearing and have relatively poor eyesight. Using their tails for balance, Chinese hamsters are good climbers and are also fast movers. Males are typically larger than females and grow to approximately ten to twelve centimeters in length.

Chinese Hamster Ovary Cells, Specimen 3

Most animal cells display a finite lifetime when isolated and grown in a tissue culture medium that supplies necessary nutrients, salts, and vitamins. Typical vertebrate cells divide between 50 and 100 times before they fail to continue cell division and eventually die. Many theories suggest that this limited life span is related to the corresponding life cycle of the parent organism from which the cultured cells were derived.

Chinese Hamster Ovary Cells, Specimen 4

Occasional changes in the genetic makeup of cultured cells allow them to propogate indefinitely, making them effectively immortal. Such lines are said to be transformed, and are often used in research as a standardized cell line. Chinese hamster ovary (CHO) cells were introduced in the early 1960s as a viable epithelial cell line containing twin female X chromosomes. The most common variety of CHO cells has a nutritional requirement for the amino acid proline, which makes this cell line an ideal candidate for genetic studies.

Chinese Hamster Ovary Cells, Specimen 5

The confocal image sequences gathered with Chinese hamster ovary cells (CHO), grown in monolayer tissue culture, were a glycosylation mutant (Lec1) expressing a secreted form of recombinant avian Thy-1 green fluorescence fusion protein.

Club Mosses

Allies to the true ferns, the club mosses and spike mosses are ancient plants distributed widely, throughout the tropics and temperate zones. One genus, Selaginella, represented by more than 700 species of small and delicate plants, is characterized by having a single, cup-shaped chloroplast per leaf and ligules, small tongue-like structures on the top of each leaf (near its base) that's function has yet to be determined.

Cork Cells

Mature cork cells are plant cells that form the protective water-resistant tissue in the outer covering of stems or trunks. Cork cells are genetically programmed not to divide, but instead to remain as they are, and are considered dead cells.

Corn Grain

Corn is the common name for the cereal grass widely grown as food for humans and animals. Along with wheat and rice, it is one of the world's chief grain crops and the largest crop grown in the USA. Native to the Americas, corn (Zea mays) is the domesticated variety of the Zea grass family, originally was cultivated by Native Americans 8,000 to 10,000 years ago.

Cup Fungus

Cup fungi are typically characterized by strikingly colorful cup-shaped mushroom-like structures that are commonly found on rotting wood in forests and in cow pastures. Some of the more brilliant colorations range from bright yellows and greens to pale peach, light orange, and deep scarlet reds.

Dandelion Root

Like other flowering plants, the roots of dandelions function to anchor the plant, gather and move water and minerals, store food, and provide a source of cells for growth.

Dinoflagellates

Dinoflagellates (Peridinium) are single-celled organisms that propel though watery environments by waving two thread-like structures referred to as flagella. These mostly marine creatures are participants in plankton communities that drift along sea currents and serve as an important source of food for many aquatic animals.

Dutchman's Pipe Vine Stem

A native of central and eastern North America, Dutchman's pipe, Aristolochia durior, is a climbing vine and part of the birthwort family. The vine is planted often as a screen or cultivated as a porch vine because it is easy and quick to grow. It is distinguished by its large heart-shaped leaves and yellowish or purplish tubular flowers that resemble traditional Meerschaum smoking pipes.

Elderberry Lenticel

Elderberry bushes can be found in most forested temperate or subtropical areas around the world. In horticulture, the bushes are often used as garden shrubs and are well known for their fruit, which is used to make wines, syrups, cordial, jellies, pies and also serves as a source of food for wildlife.

Eyelid (Human)

Dinoflagellates (Peridinium) are single-celled organisms that propel though watery environments by waving two thread-like structures referred to as flagella. These mostly marine creatures are participants in plankton communities that drift along sea currents and serve as an important source of food for many aquatic animals.

Fava Bean Mitosis

The fava bean plant (Vicia faba) also known as broad bean or horse bean, is a legume belonging to the pea family, Fabaceae. It is cultivated for its seeds, six to eight beans resembling large round limas, packed inside a large, pale-green, velvety pod.

Fern Anther

The anther is the pollen producing structure of flowering plants that is found in the male reproductive organ known as the stamen. Often referred to as the pollen sac, anthers are bi-lobed structures that typically rest atop long slender stalks called filaments.

Fern Indusium

Fern is a common name for the cryptogamous (spore-producing) plants belonging to the division Filicophyta, also called Filicinophyta. They are primitive vascular plants with true roots, stems, and complex leaves. Most ferns reproduce through the alternation of generations, alternating successive generations of sexual and asexual forms.

Fern Spores

Most ferns reproduce through the alternation of generations, alternating successive generations of sexual and asexual forms. The sexual form, called the gametophyte or prothallia, is a tiny kidney-shaped plant and difficult to find in the wild. The asexual form, or sporophyte, is represented by the fern plant as it is commonly known.

Frog Artery

The primary function of the heart is to pump oxygen rich blood to organs such as the brain, liver, and kidneys as well as all other tissue. The heart of the frog is different from the hearts of warm-blood animals such as humans.

Frog Eye (40x Magnification)

Frogs have eyes that closely coordinate with their long sticky tongues to enable these amphibians to capture fast moving prey with whip-like accuracy. A majority of species possess eyes that bulge from the sides of their heads so that most frogs can see in almost all directions.

Frog Muscle

Frogs depend on several types of muscles to carry out their normal daily activities such as pumping blood, breathing, moving about, and retrieving food. The three types of muscle are striated (skeletal), cardiac (heart), and smooth.

Frog Stomach

After outliving dinosaurs, frogs have changed very little from their ancestors who roamed the earth 150 million years ago. These slippery creatures can be found atop freshwater lily pads, among the canopies of tropical rainforests, burrowed deep into the sands of the Australian desert, or even hibernating in Arctic soil.

Frog Unsegmented Egg

Unlike their reptile cousins, which are better adapted for reproduction on land with eggs that are protected from desiccation and other harm, frog eggs need a moist environment and often are protected by a gelatinous mass.

Ginkgo Tree

The ginkgo tree has changed little in morphology based on 200 million year-old fossils. This beautiful plant is often cultivated as an ornamental tree, particularly in urban areas because it is resistant to smog.

Grape Black Rot

Black rot, caused by the fungus Guignardia bidwellii is one of the most serious diseases of cultivated grapes in the eastern United States, especially in warm, humid areas. Crop losses can be devastating, ranging from 5 to 80 percent depending on the weather, the variety of grape being grown, and the amount of disease in the vineyard.

Green Algae

Members of the Kingdom Protista, algae are most common in aquatic habitats, but occur in nearly every environment. They range in size from microscopic to giant kelp that reach 200 feet (60 meters) in length. Algae produce a significant percentage of the Earth's oxygen, are the base of the food chain for nearly all aquatic life, and provide food and industrial products for humans.

Hamster Cell Nuclei

Chinese hamster ovary (CHO) cells (sometimes Syrian hamster cells) are very popular for histological, viral, and genetic research, because they are easily cultured as animals or tissues in the laboratory and because hamsters are small, cheap, and reproduce prolifically at an early age.

Heart Thick Section

The human heart, typical of mammals, is a four-chambered hollow muscular organ, found between the lungs and enclosed in the pericardium (cardiac) cavity. The average adult heart is about five inches in length and three and a half inches at its broadest part.

Hollyhock Rust Fungus

Hollyhocks are prone to rust disease, which generally does not cause death of the plant, but does stunt growth and cause discoloration and premature shedding of leaves.

Human Bronchogenic Carcinoma

Bronchogenic carcinoma, or lung cancer, is the leading cause of cancer deaths in the United States and most of the developed world. In the 1990s, more women were dying of lung cancer than of breast cancer, which historically had been the major cancer killer in women.

Human Cerebellum

The cerebellum is the portion of the human hindbrain that ensures a movement goes where it is supposed to go, at a proper rate and with a force appropriate to the resistance being overcome.

Human Choroid Plexus

The choroid plexus is comprised of a network of minute fringed capillaries, which secrete a liquid that is vital to the health of the brain and spinal cord, termed the cerebrospinal fluid.

Human Diaphragm

The diaphragm, a layer of muscle and fibrous septum, is connected to the spine at the lumbar vertebrae by two crura or pillars. When the diaphragm muscle contracts, it moves downward, making the chest or thoracic cavity longer, while its associated intercostal muscles contract, widening the chest, allowing inspiration. The diaphragm and external intercostal muscles then relax and expiration occurs.

Human Gallbladder

Responsible for storing the bile and secreting mucous, the human gallbladder is a pear-shaped muscular sac, lodged under the right lobe of the liver.

Human Lung

The respiratory system branches similarly to a tree, with about 17 levels of branching between the trachea and the bronchioles, and results in about 130,000 bronchioles in the average pair of human lungs.

Human Meissner's Plexus

The Meissner's plexus is an interlacing collection of nerves that connects the outlying smooth muscles to the innermost mucous membranes that line the stomach and intestines.

Human Neurons

Nerve cells are one of the fundamental building blocks that separate organic matter (living organism) from inorganic matter (non-living material such as rocks). Individual nerve cells form links that join together to produce a complex and integrated communications network that runs throughout the entire body. These interconnected cells allow the living organism to communicate or interact with its external environment by transmitting information though a coordinated series of electrical and chemical signals.

Human Post Central Gyrus

The mystique of the brain intrigues modern biologists and psychologists even as it did the philosophers of ancient times. Brain function is so strongly associated with what it means to be alive and human that the cessation of brain activity is a clinical and legal criterion of death, even when other organs of the body are still functioning.

Human Submandibular Gland

The submandibular gland, one of three human saliva glands, produces about two thirds of the average daily output of one liter of saliva. The saliva produced is a viscous solution containing mucin, salts and the enzyme amylase.

Human Tongue

The primary function of the tongue in mammals is to provide a mechanism for taste. As a muscle it is also important as a means of creating the negative pressure necessary for infants to suckle, an exclusively mammalian activity.

Human Trachealis Muscle

The trachealis muscle is a thick band of smooth muscle that bridges the ends of each of the horseshoe-shaped cartilage rings that help to stabilize the entire length of the windpipe.

Human Uterus

The human uterus is a specialized organ designed for containing and nourishing a developing embryo from implantation to birth. If fertilization of the egg or ovum occurs, the epithelial lining of the uterus undergoes physiological changes that make it hospitable for the attachment and nurturing of the early embryo.

Human Vocal Cords

The term vocal cords can be somewhat misleading because these sound producing structures are not really chords but are folds of expandable tissue that extend across a hollow chamber known as the voice box. When engaged for speaking, the vocal folds can clock over 100 vibrations per second -- too fast for the unassisted eye to see.

Lichen Thallus

Lichen is an organism that results from intimate cooperation between two distinct life forms, fungi and algae. This tough and hardy partnership can live where nothing else will grow -- even on bare rock.

Lily Anther Prophase

The lilium, with its definitive reproductive stages, is a favored specimen for illustrating normal cell division. Of special interest are cross sections that present anthers during different stages of development, especially evolution of mature pollen grains from microspore mother cells.

Lily Anther Sporogenous Tissue

The anther is the pollen producing structure of flowering plants that is found in the male reproductive organ known as the stamen. Often referred to as the pollen sac, anthers are bi-lobed structures that typically rest atop long slender stalks called filaments.

Lily Anther Uninucleate Microspores

The anther has a terminal saclike architecture that contains spore-producing cells called microsporocytes, which undergo meiosis and eventually form grains of pollen.

Lily Embryo, Specimen 1

Lily is the common name for the family of Liliaceae and comprises more than 4000 species of flowering plants. Revered for thousands of years as a symbol of purity, many lilies are cultivated as highly prized ornamental plants including tulips, true lilies, daffodils, hyacinths, and amaryllis. Most members of the lily family are herb-like and are characterized by bulbs or enlarged underground storage organs that give rise to fleshy stems and erect narrow grass-like leaves -- many display beautiful showy flowers. Several species within this large family are cultivated as food crops and include such staple culinary ingredients as onions, shallots, garlic, chives, and leaks.

Lily Embryo, Specimen 2

A plant embryo is actually an immature plant that is surrounded by stored nutritive materials that are enveloped in a protective seed coat. The embryo typically consists of embryonic roots referred to as radicles, an embryonic stem, the hypocotyl, and leaf like structures, or cotyledons. Lilies are classified as monocots because they produce only a single cotyledon. This embryonic leaf absorbs nutrients from the seed package until the embryo germinates and develops into a seedling, which is able to produce true leaves that generate food through the process of photosynthesis. All seeds encase plant embryos, which remain dormant until activated by water and climate conditions that entice germination.

Lily Embryo, Specimen 3

Lily is the common name for the family of Liliaceae and comprises more than 4000 species of flowering plants. Revered for thousands of years as a symbol of purity, many lilies are cultivated as highly prized ornamental plants including tulips, true lilies, daffodils, hyacinths, and amaryllis. Most members of the lily family are herb-like and are characterized by bulbs or enlarged underground storage organs that give rise to fleshy stems and erect narrow grass-like leaves -- many display beautiful showy flowers. Several species within this large family are cultivated as food crops and include such staple culinary ingredients as onions, shallots, garlic, chives, and leaks.

Lily Embryo, Specimen 4

A plant embryo is actually an immature plant that is surrounded by stored nutritive materials that are enveloped in a protective seed coat. The embryo typically consists of embryonic roots referred to as radicles, an embryonic stem, the hypocotyl, and leaf like structures, or cotyledons. Lilies are classified as monocots because they produce only a single cotyledon. This embryonic leaf absorbs nutrients from the seed package until the embryo germinates and develops into a seedling, which is able to produce true leaves that generate food through the process of photosynthesis. All seeds encase plant embryos, which remain dormant until activated by water and climate conditions that entice germination.

Lily Flower Young Bud

The lily is an herbaceous flowering plant native to the temperate areas of the Northern Hemisphere. The name, lily, is most frequently applied to the 80-100 species belonging to the genus Lilium of the family Liliaceae.

Lumbricus (Earthworm)

The lumbricus terrestris is more commonly known as nightcrawler, earthworm, or dew worm. These soil-borne animals generally prefer moist and humid habitats and can be found in orchards, pastures, forests, and grasslands as well as crawling along sidewalks on cloudy days just after a rain.

Lung Adenocarcinoma

Lung cancers are divided into small-cell and non-small cell types including adenocarcinoma (cancers of secretory organ linings); each with its own treatment regime.

Lymph Nodes

The lymphatic system is comprised of a series of interconnected vessels, ducts, various organs, and structures that constantly circulate a clear and watery fluid that nourishes and protects tissues throughout the body. This precious fluid and its constituents are a major component of the body's immune system and the term lymph is derived form the Latin word lympha, meaning water goddess.

Mammalian Motor Neurons

Specialized nerves referred to as motor neurons transmit signals that cause skeletal muscle cells to temporarily shorten or contract. The average mass of the human body is comprised of about forty percent skeletal muscle.

Mammalian Purkinje Fibers

Purkinje fibers are heart muscle tissues that are specialized to conduct electrical impulses to ventricular cells, which induce the lower chambers of the heart to contract. Enveloped in a small amount of delicate connective tissue, these electroconductive fibers are imbedded in regular cardiac muscle.

Mammalian Trachea

The trachea or windpipe, is a part of the respiratory system and is comprised of a long slender tube that carries air to and from the lungs. In addition to serving as a passageway for air, this channel humidifies (moistens and warms) air before it reaches delicate lung tissue, and protects the respiratory tract from foreign particles.

Mammalian Vater-Pacini (Pacinian) Corpuscles

The onion-like Vater-Pacini corpuscles are mechanoreceptors found in the pancreas of cats, but not humans. In humans, the pressure-sensitive, encapsulated nerve fibers are the largest (1 to 4 millimeters in length) lamellated (layered) bodies found in skin, nipples, genitalia, ligaments, and tendons.

Marchantia Sporophyte

These mature sporophytes are the asexual reproductive form for the Marchantia order of Bryophytes, moss-like plants of the division Bryophyta, also known as liverworts, or "liver plants."

Medulla Oblongata

The medulla oblongata is a cone-shaped part of the brain that is located on the lowermost portion of the brain stem and gradually transitions into the spinal cord. This specialized area serves as the major pathway for nerve impulses that enter and leave the neural systems confined to the skull.

Melosira Diatoms

Diatoms are unicellular phytoplankton that are armored with a protective cell wall composed of silica, and these tiny creatures form the basis of the oceanic food chain.

Monkey Lip

Lips form the muscular opening of the mouth and contain numerous tiny capillaries and nerve endings just beneath the thin membrane surface. The center of the lip is comprised of a muscle termed obicularis oris, which helps to hold food in the mouth and form facial expression such as smiling and frowning.

Monocot Root Tip

Monocot plants such as lilies, orchids, palms, irises, and grasses are supplied with an extensive fibrous root system. Although a primary root initially emerges from a seedling, it remains just long enough to establish a foothold and is quickly replaced by the outgrowth of many slender roots.

Moss Capsule

Mosses are the most common, diverse, and advanced group of Bryophytes, a division of green, seedless plants that dates back to the Permian period (286 to 245 million years ago).

Moss Reproductive Tissue

Mosses are the most common, diverse, and advanced group of Bryophytes, a division of green, seedless plants that dates back to the Permian period (286 to 245 million years ago). In Bryophytes, the antheridium is the female sex organ, which produces eggs.

Mouse Intestine

Mouse intestines are very much like those of other vertebrate animals. The large intestine is wider and shorter than the small intestine and its primary function is to absorb water and electrolytes from digestive residues and store fecal matter.

Mouse Kidney

Mouse kidneys are located on the dorsal (upper) wall of the abdominal cavity and are securely held in place by fibrous capsules. Like other mammalian kidneys, the outer layer of this rodent's kidney is brownish red and granular in appearance, with a firm consistency.

Nostoc (Cyanobacteria)

The Nostoc is an aquatic form of bacteria that can be found on moist rock, along the bottom of freshwater lakes and springs, and only rarely in marine habitats. Many of these single-celled organisms form colonies that range from microscopic to macroscopic in size and are often surrounded by a gelatinous sheath.

Oak Tree Stem

Oaks, members of the genus Quercus, are deciduous, hardwood trees found throughout the world, with about 60 species native to the United States. The lifespan of an oak varies by species (from 50 to more than 200 years) and environmental condition.

Oleander Leaf

Oleander, Nerium oleander, is an ornamental evergreen that belongs to the dogbane family, Apocynaceae. The best-known oleander shrub, called rosebay, is native to the Mediterranean and Middle East regions and is distinguished by dark green leaves that are thick, leathery, and lance-like.

Onion Root Tip Mitosis

Onions are among the world's oldest cultivated plants, and their pungent bulbs have probably been used in cooking since humans have been using fire. A member of the lily family, the onion is thought to be a native of Southwestern Asia but is now grown throughout the world.

Optic Nerve Head

More commonly known as the blind spot, the optic disc does not contain sensitive light receiving cells such as cones and rods and is not capable of detecting a visual image. This region, devoid of photoreceptive cells, is where optic nerve fibers of the retina converge to leave the eyeball -- everyone has one of these blind spots in each eye.

Ovarian Adenocarcinoma

Starting in the ovaries as cysts, ovarian cancer may originate from epithelial, germ, or connective tissues, each with its own characteristics and indicated treatment. Adenocarcinomas are cancers of the ovary lining and are epithelial in tissue type.

Pacinian Corpuscle

A feature of both human and non-human primates, the Pacinian corpuscle is a mechanoreceptor that responds to pressure or any kind of mechanical stimulus that causes deformation of the corpuscle surrounding the single afferent nerve fiber.

Peyer's Patches

Peyer's patches are a collection of large oval lymph tissues that are located in the mucus secreting lining of the small intestine. These lymph nodules are especially abundant in the lowest portion of the small intestine that empties into the larger intestinal tract, an area of the digestive system referred to as the ileum.

Pine Blister Rust

White Pine Blister Rust, a serious disease of pine trees caused by the fungus Cronartium ribicola. This fungus also is a disease of the Ribes genus (currant and gooseberry bushes), which serves as an alternate host for the fungus.

Pine Cone

Pine is the common name for any species belonging to the genus Pinus, a member of the family Pinaceae, coniferous trees with needle-like leaves. Pinaceae is the largest family of conifers, consisting of about 262 species, and includes fir, larch, spruce, hemlock, cedar and Douglas fir.

Pine Embryos

Tiny pine embryos are encased within a seed coat and wait until favorable growing conditions arise before emerging. The most intensely studied pine seeds today belong to the Wollemi pine, a cone-bearing tree whose lineage dates back over 250 million years.

Pine Tree Roots

Pine trees are classified as gymnosperms and are characterized by a tap root system. When a pine seed germinates, the very first organ to appear is the primary root. As the primary root grows downward to anchor the seedling, it branches secondary roots laterally. Although species of pine trees vary, most have wide spreading but rather shallow root systems that leave them vulnerable to strong gusts of wind.

Pollen

Pollen is a seasonal problem for millions of people around the world who suffer from allergenic reactions to the antigens embedded on the outer casing of these microscopic grains. Tiny grains of pollen are released into the atmosphere by a wide spectrum of flowers, trees, weeds, grasses and other plants that reproduce seasonally.

Polypodium Rhizomes

Mostly epiphytes (plants growing above the ground, but supported nonparasitically by another plant or object), polypodium ferns are often found growing from tree trunks and limbs, but sometimes on rocks or even dry ground.

Pons

The pons is a broad, horseshoe shaped portion of the brain (often termed the brain stem) located in the upper segment of the region that gradually transitions into the spinal cord.

Potato Late Blight

Potato late blight, caused by the fungus Phytophthora infestans, is one of the most important potato diseases in the world. It was responsible for the great Irish Potato Famine of the 1840's, leaving over 1 million people dead from famine-related diseases and resulting in the exodus of more than 1.5 million people from Ireland.

Primate Cornea

As the first and most powerful lens in the optical system of the primate eye, the cornea with a crystalline lens allows the production of a sharp image at the retinal photoreceptors.

Primate Iris

Primates have evolved eyes that are uniquely adapted to their tree dwelling lifestyles and inquisitive nature. The eyes of primates are positioned on the front side of their head so they can peer forward to provide overlapping fields of view or stereoscopic vision. This three-dimensional perspective of the world permits accurate perception of distance, which is very helpful to primates swinging from branch to branch and handling food.

Primate Meissner's Corpuscles

Located in the papillae of the dermis (inner layer of primate skin) that project into the hand epidermis (skin outer layer), Meissner's corpuscles are associated with quickly-adapting (QA) mechanoreceptor fibers which respond to movements in the range of 2 to 40 millimeters per second, but do not react to constant, steady stimulation. Each Meissner's corpuscle is innervated by two to six nerves.

Primate Pancreas

The pancreas is a glandular organ that secretes digestive enzymes into the small intestine by way of the pancreatic duct. Also containing specialized groups of cells called the islets of Langerhans, the pancreas produces the hormones -- insulin and glucagon. Secreted directly into the bloodstream, these hormones work together to maintain proper sugar or glucose levels in the blood.

Primate Skeletal Muscle

Muscles are tissues composed of bundles of fibers (fascicles) having varying lengths and diameters that can shorten, thicken, or lengthen depending on the location and the message sent by the controlling neurons.

Primate Tongue

Covered in a mucous membrane, this muscular appendage is comprised of very small nodules termed papillae that project along the top surface and provide a rough, unsmooth texture. Tiny bulb-like taste organs, often referred to as taste buds, are scattered over the top surface and sides of the tongue.

Primate Trachea

The trachea is a thin walled tube that carries air to the lungs and is also commonly known as the windpipe. The tube is lined with a mucous membrane comprised of numerous tiny hairs or cilia that keep dust and other foreign particles from reaching the lungs. Material trapped in the mucous is swept out through the nose or mouth by the upward movement of the cilia.

Pumpkin Stem

Botanists are very familiar with the Cucurbita stem since it presents a clear demonstration of cell differentiation in the vascular system of a herbaceous plant.

Rabbit Muscle Fibers

Rabbit muscle is often used in biomedical research because it is a very good model of human tissue that is readily available at low costs.

Red Algae

Polysiphonia are plant-like organisms that are predominantly found in marine environments and are more commonly known as red algae. Although a few species may be found in freshwater, red algae are typically attached to rocks or other plants in tropical and subtropical deep waters or washed along shorelines.

Retina

The tiny retina of the eye is packed with more sensory nerve cells than any other organ in the body. When light enters the eye, it passes through the lens and is focused onto the retina. Comprised of light-sensitive nerve tissue located at the rear of the eyeball, the retina sends messages directly to the brain by way of the optic nerve.

Rhizopus Rot

Rhizopus rot is a soft rot of harvested or over-ripe stone fruits, such as peaches, nectarines, sweet cherries, and plums. Mold species belonging to the genus Rhizopus cause the rot, which initially appears on the fruit as a fuzzy white mass, called the mycelium.

Sweet Flag Grass

Sweet flag, Acorus calamus, is a grass-like perennial that can grow up to 2 meters or 6.6 feet high. Sweet flag, along with the common cattail, thrives in wet areas like the edges of streams, ponds, and lakes. The thick, erect leaves resemble an iris. The flowers are greenish brown cylinders covered in little rounded spikes, but they rarely flower.

Sympathetic Ganglion

Ganglions are nerve tissue masses that are principally comprised of neuron cell bodies that are located outside the central nervous system. This group of nerve cells forms many important feedback networks by connecting the brain and spinal cord to specialized tissues such as cardiac muscle, smooth muscle, and glands.

Thymus Gland

The thymus is a primary lymph organ and a key regulator of the immune system. This small structure is comprised of a mass of glandular tissue that is divided into two soft pinkish-gray lobes and is located in the upper chest above the heart.

Trichomes

Trichomes are minute highly specialized outgrowths that are found along any surface of a plant and are designed to enhance a plant's chances of survival. These accessory structures occur most often along stems and leaves but can also be found on the surface of petals and also comprise the fragrant and sweet necturaries that draw pollinating creatures.

Ulothrix

Ulothrix is a green filamentous freshwater green algae that can reproduce asexually with zoospores that are formed when the environment becomes less favorable.

Umbilical Cord

Literally the lifeline between the developing fetus and mother, the umbilical cord is a long, flexible structure consisting of two arteries and one vein surrounded by a gelatinous matrix. The placenta, which connects the mother to the umbilical cord, is an organ that develops in her uterus during pregnancy, which provides nutrients and oxygenated blood for the fetus and eliminates its waste products..

Wheat Flower

Wheat is the common name for any of the cereal grasses belonging to the genus Triticum and is an important food source for people around the world. Evidence shows that wheat grew as a wild grass in the Middle East nearly 10,000 years ago and was in cultivation by 6,000 BC.

Wheat Loose Smut

Loose Smut is a fungal disease that replaces developing kernels of wheat grain with black powder-like masses of spores. This pathogenic fungus, referred to by scientists as Ustilago tritici, quietly infects the seeds of cereal crops and stays dormant until spring. Large clouds of black dust arising from combine operations on farms during wheat harvest often reveal smut infestation.

Wheat Rust

Wheat rust is a common and serious disease, reducing crop yields both in the United States and in other wheat-growing areas of the world. The disease is caused by a parasitic fungus and can affect both the leaf and stem of wheat plants.

Wood Cells

Wood cells, like other plant cells, have cell walls that are absent in animal cells. The three major constituents of a wood cell are cellulose (40 to 50 percent), lignin (23 to 33 percent in softwoods; 16 to 25percent in hardwoods), and hemicellulose. Many important properties associated with wood are related to the crystalline nature of cellulose in wood cells.

Zamia Young Ovule

Although similar in form to palm trees, Zamia are dioecious, meaning that the male and female reproductive organs are borne on separate plants. The ovules of the cycads are naked as they are in other ancient seed plants (Gymnosperms) and unlike the flowering plants (Angiosperms) that hold their ovules in ovaries.

Zea (Corn) Smut

Smut is a disease of cereals, corn, grasses, onions, and sorghum that can be caused by any of more than 700 species of parasitic fungi. Smuts generally have a negative economic impact on agriculture, because they affect so many food crops. An exception to this is corn smut, which is considered a delicacy in Mexico.

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